1. Field of the Invention
The present invention relates to an electrode tool for electrochemical machining and a method of manufacturing the same, and, more particularly, to a highly-durable electrode tool for electrochemical machining, which can prevent the corrosion and abrasion of a conductive pattern at the time of electrochemical machining for forming dynamic pressure-generating grooves of a fluid dynamic bearing, and a method of manufacturing the same.
2. Description of the Related Art
Electrochemical machining (ECM) is a method of etching fine grooves in a metallic material, which is a workpiece, by removing a metal oxide layer, which forms when the metallic material is electrochemically dissolved, and is used to form fine dynamic pressure-generating grooves in a fluid dynamic bearing.
In such a method of forming dynamic pressure generation grooves in a fluid dynamic bearing, positive current is applied to a bearing member in which dynamic pressure-generating grooves are to be formed, negative current is applied to an electrode tool in which a conductive pattern corresponding to the dynamic pressure-generating grooves is formed, and a high-pressure electrolyte flows between the bearing member and the electrode tool, thereby the dynamic pressure-generating grooves are electrochemically etched in the bearing member in the form of the conductive pattern.
Therefore, in order to conduct the electrochemical machining, a conductive pattern must be formed in an electrode tool in the form of dynamic pressure-generating grooves, and the electrode tool must not be abraded by a high-pressure electrolyte, and must be electrochemically durable.